SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed25d691aa313d30ef520d591ed3e8ca878624f21cf0fda3db30bdbb2e24d13f' 
  AND token = 'gKlFLZj0ph/o++L24eic9BdiJDo8QJsHh+YbP/9Kglo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}